D&D General what is it that make certain monsters of certain categories?

[Mind of tempest]

why are some monsters aberrations and other monstrosities what is the common link for those categories over the years?
we know what dragons and giants are easy and the many types of spirits in dnd are well known but what is it that separates those two categories?
is it thematic? appearance? something else? a combination?
given my past interest in building a playable aberration and my inability to get it to feel right, I throw myself upon your mercy and seek answers to this problem.

yes, I do know the categories are arbitrary but so is most things in this world so that does not matter?

 

[Voadam]

Aberrations are generally unnatural and Cthulhu mythos type otherworldly.

Monstrosities are more magical creature based. So manticores and displacer beasts.

It is a lot of judgment calls and not something as easy as tentacles (see displacer beast and kraken). Something with rubbery skin is more likely to be an aberration though.

 

[Voadam]

Spirits are not straight forward.

Outsider, undead, fey, elementals all work for the 3e/d20 classifications.

 

[Voadam]

The classifications started in 3.0 with aberrations and magical beasts.

The tying of mechanical stats to type led to some weirdness as ropers were magical beasts and not aberrations to gain the 1/1 BAB of beasts while aberrations would have stuck them with 3/4 BAB advancement. I house ruled them in my game to be aberration type with magical beast type stats.

 

[Mind of tempest]

so I ta

Aberrations are generally unnatural and Cthulhu mythos type otherworldly.

Monstrosities are more magical creature based. So manticores and displacer beasts.

It is a lot of judgment calls and not something as easy as tentacles (see displacer beast and kraken). Something with rubbery skin is more likely to be an aberration though.

can you elaborate on the unnaturalness of them, I gathered the otherworldly but I want to make it easier to get than that as alien can also merely mean off-world?

Spirits are not straight forward.

Outsider, undead, fey, elementals all work for the 3e/d20 classifications.

true there but they are at least a well-gathered group of categories with some definition between them?

The classifications started in 3.0 with aberrations and magical beasts.

The tying of mechanical stats to type led to some weirdness as ropers were magical beasts and not aberrations to gain the 1/1 BAB of beasts while aberrations would have stuck them with 3/4 BAB advancement. I house ruled them in my game to be aberration type with magical beast type stats.

what makes you think ropers are aberrations fundamentally it has to be more than has tentacles and is strange?

 

[Voadam]

Most monstrosities I think of an animal as a base with magic added on, so the chimera is three melded animals with some magic powers. A displacer beast is a six legged panther with shoulder tentacles and a magic power.

A roper looks like it is not at base an animal, other than having an eye and a mouth. Aberrations can have weird anatomy and body consistency. Enough mutational transformation will turn things into aberrations.

My conceptions of the categories were formed a lot by the 3e type definitions and a lot of the original categorization done in 3e.

"An aberration has a bizarre anatomy, strange abilities, an alien mindset, or any combination of the three."

"Magical beasts are similar to animals but can have Intelligence scores higher than 2.
Magical beasts usually have supernatural or extraordinary abilities, but sometimes are merely bizarre in appearance or habits."

A roper fits more into an aberration definition to me than a magical beast one.

 

[Tonguez]

Monstrosities are things with discernable anatomies and internal systems which ought to be familiar to natural philosophers.

Abberations are those things whose anatomies are not so naturally discernible or logically formed.

the best way to categorise Ropers as monstrosities is to think of them as a bizarre form of terrestial sea anemones

unfortunately 5e has been rather inconsistent

 

[BookTenTiger]

In the Monster Manual it says:

Monstrosities are monsters in the strictest sense — frightening creatures that are not ordinary, not truly natural, and almost never benign. Some are the results of magical experimentation gone awry (such as owlbears), and others are the product of terrible curses (including minotaurs and yuan-ti). They defy categorization, and in some sense serve as a catch-all category for creatures that don’t fit into any other type.

So it's almost like Monstrosity is a general term that describes all monsters, unless they fit into a more specific category.

An Aberration, according to the Monster Manual, is:

Aberrations are utterly alien beings. Many of them have innate magical abilities drawn from the creature’s alien mind rather than the mystical forces of the world. The quintessential aberrations are aboleths, beholders, mind flayers, and slaadi.

So a Beholder could be categorized as a Monstrosity, but because it is an alien being with magical abilities drawn from its mind, it fits into Aberration.

 

[Mind of tempest]

Most monstrosities I think of an animal as a base with magic added on, so the chimera is three melded animals with some magic powers. A displacer beast is a six legged panther with shoulder tentacles and a magic power.

A roper looks like it is not at base an animal, other than having an eye and a mouth. Aberrations can have weird anatomy and body consistency. Enough mutational transformation will turn things into aberrations.

My conceptions of the categories were formed a lot by the 3e type definitions and a lot of the original categorization done in 3e.

"An aberration has a bizarre anatomy, strange abilities, an alien mindset, or any combination of the three."

"Magical beasts are similar to animals but can have Intelligence scores higher than 2.
Magical beasts usually have supernatural or extraordinary abilities, but sometimes are merely bizarre in appearance or habits."

A roper fits more into an aberration definition to me than a magical beast one.

Monstrosities are things with discernable anatomies and internal systems which ought to be familiar to natural philosophers.

Abberations are those things whose anatomies are not so naturally discernible or logically formed.

the best way to categorise Ropers as monstrosities is to think of them as a bizarre form of terrestial sea anemones

unfortunately 5e has been rather inconsistent

In the Monster Manual it says:



So it's almost like Monstrosity is a general term that describes all monsters, unless they fit into a more specific category.

An Aberration, according to the Monster Manual, is:



So a Beholder could be categorized as a Monstrosity, but because it is an alien being with magical abilities drawn from its mind, it fits into Aberration.

so how does one successfully make some aberrations as I can't get the feeling right as it is clear I only make monstrosites?

 

[Baldurs_Underdark]

so how does one successfully make some aberrations as I can't get the feeling right as it is clear I only make monstrosites?

You probably start off with an alchemy lab, a small library of magical books, a pentagram and a few years of spare time.